codex-context-diet

# Context Diet

Codex re-reads its whole desk before every reply. This plugin keeps the pages that still matter and clears the ones you can reprint.

<img src="assets/context-diet.jpg" alt="Two panels. On the left a desk is buried under a tall pile of printed pages. On the right the same desk holds one page and two sticky notes" width="100%">

A Codex plugin that asks TypeSafe's [Jev](https://typesafe.ai/) which bulky tool results the session still needs, then replaces the rest with a bounded head and a one-line note.

Long sessions fill up with tool output. Test logs, build noise, large file reads, MCP payloads. Once a result lands in the transcript, Codex re-sends it on every later request until compaction summarises it away. Compaction runs after the context is already bloated. This plugin works at the moment the result is produced.

## Why you'd install it

- **You don't change how you work.** No new commands, no habits. Install it, click trust once, forget it.
- **Your long sessions stay sharp.** This matters most in the sessions that go on for an hour with lots of commands. That's where the desk would otherwise be buried.
- **It rarely makes you wait.** It only looks at big outputs, roughly a page and a half of dense text and up. Small stuff it ignores completely, and that costs you nothing.

## How it works

1. `PostToolUse` fires after a tool produces output. The adapter reads one JSON payload on stdin.
2. Results are left alone when they are small, come from `apply_patch`, name a tool in `neverDietTools`, or arrive as the first result of a session.
3. Everything else goes to Jev in one request carrying five literal questions, and the answer decides.
4. When the body is stale, Codex replaces the tool result with the first `truncateHeadChars` characters and a not